Clock utilizing a magnetic escapement mechanism

ABSTRACT

A clock of the magnetic escapement type having a cyclically impulsed tuning fork mounted between frame plates which are formed of metal and synthetic resin, respectively. The tuning fork is secured to the edge of a base plate having a body portion which lies between the legs of the tuning fork and having a mounting portion. The base plate has a deep notch adjacent the region of securing of the tuning fork and the mounting portion engages a block of damping material secured to the frame. One leg of the tuning fork cooperates with a magnetic escapement wheel mounted upon an escapement shaft which is vertically oriented. The escapement shaft has a worm driving a worm wheel in such a way that the reaction force of the worm wheel acts in a direction opposite to the action of gravity. The worm is of special antifriction construction consisting of a coil spring with the corresponding portion of the shaft being annularly relieved. The escapement shaft has a flywheel with a manual wiper for starting purposes with the flywheel being loose upon the shaft.

United States Patent [191 Hirose 1 CLOCK UTILIZING A MAGNETIC ESCAPEMENT MECHANISM [75] Inventor: Masakazu Hirose, Kanag awa, Japan [73] Assignee: Jeco Kabushiki Kaisha,

Kanagawa-ken, Japan 22] Filed: Mar. 13, 1973 21 Appl. No.:340,646

[58] Field of Search. 58/23 R, 23 AC, 23 D, 23 TF, 58/23 V, 7,116 R, 116 M, 117, 28 R, 128 D; 310/15, 21, 20, 80, 23, 36, 37, 74

[56] References Cited UNITED STATES PATENTS 3,171,991, 3/1965 Baumer 58/23 TF 3,208,287 9/1965 lshikawa et a1. 58/11'6M 3,212,252 10/1965 Nakai 58/23 R 3,277,644 10/1966 ,Nomura et a1. 58/23 R 3,433,984 3/1969 Tschudin 58/23 R 3,504,301 3/1970 Hetzel 58/23 TF 3,532,912 10/1970 CliffordJ... 58/116 R 3,566,167 2/1971 Raval 58/23 X 3,577,874 5/1971 Mutter 310/25 X [45] June4,1974

3,609,958 Bertsch et a1 58/23 V [57] ABSTRACT A clock of the magnetic escapement type having a cyclically impulsed tuning fork mounted between frame plates which are formed of metal and synthetic resin, respectively. The tuning fork is secured to the edge of a base plate having a body portion which lies between the legs of the tuning fork and having a mounting portion. The base plate has a deep notch adjacent the region of securing of the tuning fork and the mounting portion engages a block of damping material secured to the frame. One leg of the tuning fork cooperates with a magnetic escapement wheel mounted upon an escapement shaft which is vertically oriented. The escapement shaft has a worm driving a worm wheel in such a way that the reaction force of the worm wheel acts in a direction opposite to the action of gravity.

The worm is of special anti-friction construction consisting of a coil spring with the corresponding portion of the shaft being annularly relieved. The escapement shaft has a flywheel with a manual wiper for starting purposes with the flywheel being loose upon the shaft.

12 Claims, 11 Drawing Figures PATENTEDJUN 4 ran sum 2 or 4 CLOCK UTILIZINGA MAGNETIC ESCAPEMENT MECHANISM The present invention relates to a clock utilizing a magnetic escapement mechanism which is of simplified construction with a reduced number of parts, using only a single jeweled bearing, which is easy to assemble, whichhas lower material cost and improved shock resistance while maintaining a high degree of accuracy.

In all the clocks of this type which have conventionally been proposed, a fine adjustment has been re quired in the coupling between the magnet on the tuning fork, or oscillator, and the magnetic escapement wheel so as to avoid malfunction upon endwise shock being applied'to the escapement shaft. To this end, it has been considered necessary to make the entire frame of metal such as brass and it has been necessary to assemble the related parts carefully.

Furthermore, it has been very difficult to avoid use of a full set of jewels on the escapement shaft.

These disadvantages are avoided by the present invention which provides an improved clock utilizing a magnetic escapement mechanism which may be mass produced using a minimum number of parts and without exercise of greatcar e in assembly.

It is a general object of the present invention to provide a clock utilizing a magnetic escapement mechanism which is distinguished by high accuracy and shock resistance but which may be mass produced at low cost using a minimum number of parts and a minimum number of assembly steps. It is another object of the invention to provide a clock using a tuning fork or the like as an oscillating element which is highly efficient, requiring a minimum amount of driving energy, being distinguished by a high Q but which nevertheless is extremely quiet in operation. with a high degree of isolation between the oscillating member and frame. It is another but related object of the present invention to provide a clock of the magnetic escapement type in which the escapement shaft is constructed and arranged to minimize bearing friction and to secure transmission of the output energy with minimum frictional waste. It is a related object to provide a magnetic escapement wheel and shaft which requires use of only a single jeweled bearing instead of the two normally required.

is a further object to provide a clock mechanism of the magnetic escapement type which is positive starting upon being manually impulsed.

Other objects and advantages of the invention will become apparent upon reading the attached detailed description and upon reference to the drawings in which:

FIG. I is an exploded perspective view, partially schematic, showing a clock utilizing a magnetic escapement mechanism according to the present invention.

FIG. 1a is a detailed view of the starting member.

FIG. 2 is a perpsective view of the magnetic escapement mechanism and associated elements in partial section.

FIG. 3 shows on an enlarged scale the worm and worm wheel.

FIG. 4 is a chart illustrating the general efficiency of V the worm with the lead angle as abscissa and the efficiency as ordinate.

FIG. 5 is a fragmentary side view of the magnetic escapement mechanism of interest with respect to startmg.

FIG. 5a is a fragment showing the lower jeweled bearing in cross section.

FIG. 6 is an elevation corresponding to FIG. 5.

FIG. 7 is a chart illustrating the manner in which the magnetic escapement wheel is started, with the time as abscissa and the velocity as ordinate comparing characteristic A of the present invention and characteristic B e of the prior art.

FIG. 8 is an exploded fragmentary perspective view showing the support for the tuning fork as dismantled.

FIG. 9 is a fragmentary perspective view of the minute wheel.

While the invention has been described in connection with a preferred embodiment, it will be understood that I do not intend to be limited to the particular embodiment shown but intend, on the contrary, to cover the various alternative and equivalent constructions included within the spirit and scope of the appended claims.

Referring to the drawings there is shown a housing 11 which is preferably made of transparent or translucent synthetic resin. The housing has a battery enclosing portion 12, providing battery contacts l4, l5, and a mechanism enclosing portion 13.

For the purpose of starting the clock, as will be described, the housing provides access to a manually actuated starting member or wiper 16 which is pivoted at 17 and which has an outwardly projecting knob 20 ex tending through a suitable clearance opening. At the upper end of the starting member 16 is a tip 22 which is positioned to engage the hub of a flywheel to be described. The member has an integral spring 18 at its lower end which biases the member normally to a disengaged position. In operation the member is moved to the left and then released, with the return movement serving to impulse the mechanism.

Mounted within the housing are two frame plates 24 and 31. The plate 31 is preferably formed of synthetic resin while the plate 24 is formed of metal. The plate 24 serves to mount a magnetic escapement wheel 25 on an escapement shaft 27. The shaft at its upper end engage a bearing 28 and at its lower end a bearing 29, the bearing 29 being detailed in FIG. 5a. The means employed for inducing rotation in the magnetic escapement wheel 25 will be described in a subsequent section. Continuing with the description of the escapement assembly, it includes a flywheel 23 having a hub 47 which is freely rotatable with respect to the shaft 27. Encircling the hub 47 is a small annulus 48 of friction material such as rubber and which is placed in alinement with the tip 22 of the starting member (see FIG. 5.).

In accordance with one of the aspects of the present invention, movement of the shaft 27 is transmitted to the gear train via a worm and worm wheel connection. As shown in FIG. 3, the worm in the presentinstance is formed by a coil spring 45 which encircles the shaft 27 and which is connected to-the shaft only at its ends. The central portion of the spring, that is, the portion engaged by the worm wheel, indicated at 43, is annularly relieved as shown at 44, being reduced to a minor diameter a. The wire of which the coil spring 45 is formed may, for example, be light gage smoothly- 3 surfaced stainless steel. The annular relief 44, permitting deeper engagement of the teeth on the worm wheel, brings about a number of advantages, one of the most important of which is the increase in efficiency. Efficiency 11 of the worm may be generally expressed by the following equation:

17 cosa y. tan 'y/cosa tan 7 ,u; tan y 1 where 17 efficiency,

an pressure angle,

u coefficient of friction,

7 lead angle. Assumed M/cosa tan p,

then

n=tan a/tan (a+p) 2 As seen in the curves of FIG. 4, therefore, 1 is sharply lowered at a and almost no variation of 1 occurs at 25 a 65. When the rotating force is transmitted from the worm to the worm wheel, the efficiency takes the maximum value at y 45 p/ 2 and depends on selection of the lead angle 7 under the necessary condition that u. should be sufficiently small from the restriction in. design of the pressure angle a For a wheel of sufficiently small module for compact design, the lead angle 7 is generally selected from a range between 10 and in view of the fact that the diameter of pitch circle would be reduced and the upper limit of strength would be encountered when a large lead angle 7 is intended.

The preferred embodiment of the present invention which employs a lead angle of 12 under consideration of the above mentioned problems assures a transmitting efficiency of about 80 percent. It is found that use of a plastic material for the worm wheel 43 is highly advantageous where stainless steel is used for the worm.

Not-only does the use of finely drawn spring wire provide a surface which is substantially friction free, but the floating movement of the spring permits any shock to be absorbed and any variations in the transmitted torque to be largely equalized.

As a further feature of the invention the direction of rotation of the escapement shaftand the hand of the worm are such that the reaction force of the teeth of the worm wheel acts in an upward direction, that is, a direction which tends to lift the vertical shaft 27 endwise against the force of gravity, thereby reducing the axial bearing pressure which acts at the lower jeweled bearing 29, a jeweled bearing being provided only at the lower end of the shaft. Reduction in the bearing load at the lower end of the shaft, assuming proper lubrication, naturally decreases the power lost in friction. Thus by reason of minimizing driving friction, at the worm, and bearing friction, the present clock requires a minimum of driving torque to be imparted by the oscillatory system next to be described.

In carrying out the present invention the magnetic oscillator, which drives the magnetic escapement wheel, is in the form of a tuning fork which is made of a bent strip of metal having opposed legs 32, 36 with a bend, or bight 51 forming a mounting base. For driving the tuning fork a solenoid type coil 39 cooperates with an armature 37 in the form of a small permanent magnet. The latter is secured to a bracket 38 which is welded or otherwise secured to the end of the leg 32. The coil 39 is supplied with alternating electrical impulses at a timed rate originating in a solid state timing circuit per se well known in the art and which does not form a part of the present invention. Vibration in the leg 32 induces vibration in the opposite leg 36. Secured to the tip of the opposite leg is a horsehoe magnet 34 which straddles the escapement wheel. The escapement wheel is provided with a series of teeth 35 and a series of spokes out of register therewith, the teeth and spokes together defining a zig-zag magnetic path which encircles the escape wheel. Thus when the horehoe magnet 34 is vibrated backwardly and forwardly in a horizontal direction, the poles thereon, in passing from a spoke to a tooth and back again, causes the escapement wheel to rotate at a speed which is dependent upon the speed of vibration and the number of cycles of magnetic irregularity in the wheel. The period of natural vibration of the tuning fork preferably corresponds to the period of the impulses supplied to the coil 39 so that the system operates in a condition of resonance.

In accordance with one of the aspects of the present invention the efficiency of the oscillating system in the condition of resonance, referred to as the Q factor, is enhanced by the manner in which the tuning fork is mounted. For this purpose I provide a base plate 41 having a body portion 50 and mounting portion 52. The body portion of the base plate is vertically arranged and centered between the legs of the tuning fork with the edge thereof secured by welding or the like to the center of the base or bent portion 51 of the tuning fork. ln carrying out the invention the base plate 41 is sharply reduced in section by forming a deep notch 49 between the body 41 and mounting portion 52, the notch extending inwardly from a region adjacent the point of attachment of the tuning fork and extending parallel to the latter. Such notching, or relief, provides the base plate with lateral freedom and permits the base plate to resiliently yield at the region of attachment of the tuning fork. It is found that this results in a number of advantages. in the first place energy is more efficiently transmitted from the driving leg 32 of the tuning fork to the driven leg 36 with minimum absorption of the vibrational energy in the base plate or base plate mounting. In short, the provision of the deep notch 49 serves to isolate the vibratory system from its mount which not only sharply reduces the amount of energy transmitted to the mount but results in a substantial increase in the efficiency of Q factor of the oscillatory system, enabling the latter to be driven with a minimum amount of electrical energy. An important by-product advantage is that the amount of vibration imparted to the frame of the clock, and to the housing, is reduced to a fraction of that normally experienced, so that the present clock runs much more quietly than clocks of This spacer block, which is illustrated at 42 in FIG. 8, because of its mass, serves to dampen vibration emanating from the mount 52. Preferably, the block 42 is formed of sintered metal or alloy. A sintered body may be produced by molding brass powders preferably of less than 150 mesh, either by itself or with addition of lead powder with heat and compression to the point of incipient fusion and to a density which is about 80 percent of the density of the raw material. Not only does the sintering permit the economic manufacture of a relatively massive block of high dimensional accuracy, but the porous nature of the result has been found to improve the dampening characteristics and to still further reduce the amount of energy transmitted to the clock frame.

It is found that using a dampening block 42 on one side of the mount 52 suffices. The plate 311 on the other side being formed of synthetic resinous material acts, of itself, as a poor transmitter of vibrational energy with high dampening effect. The parts are clamped together by means of a machine screw 53 which passes through the plate 24, block 42, mount 52 and then the plate 31 with a nut holding the sandwich thus formed tightly and permanently together.

For the purpose of providing a vernier type regulation of the frequency of vibration in a resonant condition, an adjusting screw is threaded into the plate 24. The adjusting screw, which is spring loaded to prevent wandering of the adjustment, carries a small permanent magnet 61 at its tip, which magnet has the effect of slowing the vibration of the leg 36 depending upon the degree of proximity. It is found that once adjusted a clock constructed inaccordance with the present designs all operate for long periods with a high degree of accuracy. The driving circuitry for the coil 39 may be selected with components having a high degree of stability, the components being sufficiently compact as to permit mounting within a small capsule 40 within the clock housing.

For the sake of simplicity the conventional gear train which is interposed between the worm wheel 43 and the clock hands has been omitted. It will suffice to say that reduction gears interposed between the wheel 43 and the minute hand 62, including-a minute wheel 55, (FIG. 9), drive the minute hand and seconds hand at the proper timed rate with respect to the clock dial 65. The hour hand 63 is driven by the usual set of 12:1 step down gearing (not shown). For the purpose of setting the minute hand a shaft 56 on the minute wheel 55 terminates in a knob 57 which projects through the rear of the clock housing. in addition, if desired, the hands may be adjusted from the underside of the clock by means of the pinion 59 which is mounted upon a downwardly extending shaft and which engages a set of gear teeth 58 on the minute wheel.

in assembling theclock the frame structure formed of the plates 31, 24 which mount the oscillator and escapement, as well as the necessary step down gearing, is secured to the front plate, indicated at 60, on which the dial 65 is mounted, and the clock hands are applied. The assembly thus formed is slipped into the clock housing and secured with suitable mounting screws (not shown). A battery is then snapped into the space 12.

A clock of the present type requires application of a starting impulse to the escapement wheel. This is accomplished by moving the starting member 16 to the left and releasing it, whereupon the tip 22 of the member engages the frictional ring 48 on the flywheel hub 47 with a wiping action. As stated, the flywheel 23 is not keyed to the escapement shaft but is slidably mounted upon it. As a result, only limited torque is ap plied, by friction, to the escapement shaft so that the shaft is rotated at a relatively slow speed into the synchronization band. The synchronization band is indicated at C in FIG. 7 and is the range of speed within which the escapement wheel will synchronize. By reason of impositive driving of the escapement shaft upon starting, the speed of such shaft follows curve A which becomes asymptotic with the synchronous speed 11,, of the escapement wheel. When the speed n is reached the oscillatory system takes over the control and driving of the escapement wheel. It is to be particularly noted that when the oscillatory system takes over control it does not have to make any sudden alteration in the speed of the flywheel which gradually assumes the same speed as the shaft upon which it is mounted. In effect, the impositive connection between the shaft and flywheel prolongs the time duration during which the magnetic escapement wheel operates within the synchronous band which not only facilitates synchronism but which prevents the magnetic escapement wheel from rotating at twice synchronous velocity. This is to be contrasted with certain prior clocks in which the starting member acts directly upon the shaft which carries the escapement wheel, causing the escapement wheel to pass quickly through the synchronous band, greatly overshooting, as shown at B in FIG. 7. The velocity transverses the synchronous band too rapidly to permit synchronization and the overshoot runs the risk that locking in may occur at twice synchronous velocity. In short, because of the construction and arrangement of the starting elements, including the source of bias, the clock may be positively started by moving the knob 20 and simply letting it go without exercise of any skill or judgment whatsoever.

The clock which has been described will be seen to amply fulfill the objects set forth above. With only a minute alternating current in the coil 39, vibrations of substantial amplitude are set up in the leg 32 of the tuning fork. Because of the effective vibrational isolation brought about by the notch in the base plate, and because of the dampening effect of the sintered block 42, the vibratory system is substantially isolated and operates, at resonance, with an extremely high Q factor. This results in a correspondingly high amplitude of vibration of the remaining leg of the tuning fork, causing the escapement wheel to be advanced in the driving direction. While the resulting torque is limited, it is, in

the present construction, sufficiently high as to be reliable and very little of the rotational energy is dissipated in the form of friction. A jeweled bearing 29 at the lower end of the escapement shaft minimizes bearing friction which is still further reduced by utilizing the re action force of the worm wheel to counteract the effect of gravity. Similarly, because of the full engagement and smooth driving surfaces at the worm, substantially all of the driving torque is effectively utilized in rota tion of the worm wheel. As a result, the clock in spite of its low power input has a safe margin of driving power so that it may provide reliable operation even in the face of accumulation of dirt and the like occurring over a period of time.

A clock of the present design has been found to be unusually resistant to shock or vibration applied in any direction.

Finally, the clock is highly economical, being substantially maintenance-free and constructed of a minimum number of simply formed, and easily assembled, parts.

What is claimed is:

l. in a clock construction the combination of a frame comprising a pair of frame plates horizontally spaced from one another, a resilient vibrating member extending horizontally between the plates and mounted at one end with respect to the plates while the other is free to vibrate horizontally, means including a coil energized by alternating current for cyclically impulsing the vibrating member, a magnet mounted on the vibrated end of the member for moving with it in a horizontal plane, a magnetic escapement wheel mounted in a horizontal plane adjacent the vibrated member and having a zig-zag magnetic path cooperating with the magnet to induce rotation in the wheel, said wheel having an escapement shaft which extends vertically between the plates, vertically spaced bearings including a lower thrust bearing secured to one of the plates for engaging the respective ends of the escapement shaft, the shaft having a worm and cooperating worm wheel, the direction of rotation of the shaft and the hand of the worm being such that the endwise reaction force of the worm wheel upon the worm is such as to tend to lift the shaft thereby to reduce the endwise gravitational force exerted at the lower thrustbearing, and a regulator in the form of a small permanent magnet in the vicinity of the vibrating member, the regulator including means on the frame for adjustably mounting the permanent magnet for movement toward and away from the vibrating member.

2. The combination as claimed in claim 1 in which the worm is in the form of a coil spring on the escapement shaft and in which the escapement shaft is annularly relieved in the region of engagement of the worm wheel'to permit increased meshing of the wormwheel free of any-interference with the tips of the teeth on the latter, the coil spring being of light gage smoothly surfaced wire engaging the shaft only at the ends thereof and floating in between.

3. In a clock mechanism the combination comprising a frame, a tuning fork formed of a flat strip bent into U-shape to define a curved base and first and second legs arranged parallel to one another, a flat base plate centered between the legs of the tuning fork and parallel to the latter, the base plate having a body portion and a mounting portion, the mounting portion of the base plate being clamped to the frame, the body portion of the base plate having one edge secured in centered position inside the curve of the base of the tuning fork, means including a coil and source of a-c. for cyclically impulsing the first leg of the tuning fork, a magnet secured to the second leg of the tuning fork, a magnetic escapement wheel cooperating with the magnet and having a shaft mounted in the frame, the wheel having a zig-zag magnetic path thereon so that it is progressively advanced as the magnet oscillates back and forth, the base plate being of sharply reduced section in the region between the body portion and the mounting portion so as to permit relatively free resilient movement of the body portion on which the tuning fork is mounted thereby to facilitate transfer of energy from the first leg of the tuning fork to the second leg while minimizing transfer of energy to the frame, and indicator means coupled to the escapement wheel shaft.

4. The combination as claimed in claim 3 in which the base plate is deeply notched between the body portion and the mounting portion, the notch extending inwardly from the region adjacent the point of attachment of the tuning fork and extending parallel to the latter.

5. The combination as claimed in claim 3 in which a relatively massive spacer block is interposed between at least one of the plates and the mounting portion of the base plate to inhibit transmission of vibrational energy from the base plate to the frame.

6. The combination as claimed in claim 5 in which the block is in the form of porous sintered metal for damping vibrations of the mounting portion of the base plate.

7. In a clock the combination comprising a frame, a magnetic escapement wheel having a shaft mounted in the frame, a vibrated element mounted on the frame at one of its ends, means for cyclically impulsing the vibrated member, the vibrated element having a magnet at the other end for cooperating with the escapement wheel so that the wheel is timingly advanced as the magnet oscillates back and forth, a flywheel having a hub frictionally slidable on the shaft, a manually operated starting member having means for wipingly engaging the hub to initiate rotation of the magnetic escapement wheel, and indicator means coupled to the escapement shaft.

8. The combination as claimed in claim 7 in which the starting member is in the form of a pivoted lever having a tip which frictionally engages the hub with a wiping action, the lever including means for normally biasing the same out of engagement with the hub but manually movable into engagement therewith and with the biasing force serving to impulse the flywheeel forwardly when the wiper is manually released.

9. The combination as claimed in claim 1 in which the shaft has a single jeweled thrust bearing at the lower end.

10. In a clock construction the combination comprising a synethetic resin plate and a metallic plate horizontally spaced from one another, two vibrating members interposed between said plates for horizontal vibrating motion, a magnet mounted on the tip of one of said vibrating members for horizontal vibrating motion, a vertical escapement shaft having a magnetic escapement wheel and an inertia wheel mounted thereon in a horizontal plane, and having a worm mounted thereon for cooperation with a worm wheel, said escapement wheel having a zig-zag magnetic path for magnetic coupling with said vibrating magnet, and a regulator mounted on the metallic plate for regulating the frequency of vibration, the regulator being in the form of a small permanent magnet arranged in the vicinity of one of the vi- I brating members and having a screw threaded in the metallic plate for adjustably positioning the permanent magnet toward and away from the one vibrating member.

11. The combination as claimed in claim 10 further comprising: a time gear wheel disposed in a vertical plane and coupled to the worm wheel, said gear wheel having a regulator shaft rigidly fixed to its center and extending horizontally from and perpendicular to said vertical plane a distance far enough to provide access vertical plane; a vertically extending regulator shaft having a horizontally disposed gear wheel at one end for coupling to the annular gear teeth, the other end of said shaft extending a sufficient distance to provide access to it, thereby providing means for adjusting said time gear wheel to a reference point.

l l l l 

1. In a clock construction the combination of a frame comprising a pair of frame plates horizontally spaced from one another, a resilient vibrating member extending horizontally between the plates and mounted at one end with respect to the plates while the other is free to vibrate horizontally, means including a coil energized by alternating current for cyclically impulsing the vibrating member, a magnet mounted on the vibrated end of the member for moving with it in a horizontal plane, a magnetic escapement wheel mounted in a horizontal plane adjacent the vibrated member and having a zig-zag magnetic path cooperating with the magnet to induce rotation in the wheel, said wheel having an escapement shaft which extends vertically between the plates, vertically spaced bearings including a lower thrust bearing secured to one of the plates for engaging the respective ends of the escapement shaft, the shaft having a worm and cooperating worm wheel, the direction of rotation of the shaft and the hand of the worm being such that the endwise reaction force of the worm wheel upon the worm is such as to tend to lift the shaft thereby to reduce the endwise gravitational force exerted at the lower thrust bearing, and a regulator in the form of a small permanent magnet in the vicinity of the vibrating member, the regulator including means on the frame for adjustably mounting the permanent magnet for movement toward and away from the vibrating member.
 2. The combination as claimed in claim 1 in which the worm is in the form of a coil spring on the escapement shaft and in which the escapement shaft is annularly relieved in the region of engagement of the worm wheel to permit increased meshing of the worm wheel free of any interference with the tips of the teeth on the latter, the coil spring being of light gage smoothly surfaced wire engaging the shaft only at the ends thereof and floating in between.
 3. In a clock mechanism the combination comprising a frame, a tuning fork formed of a flat strip bent into U-shape to define a curved base and first and second legs arranged parallel to one another, a flat base plate centered between the legs of the tuning fork and parallel to the latter, the base plate having a body portion and a mounting portion, the mounting portion of the base plate being clamped to the frame, the body portion of the base plate having one edge secured in centered position inside the curve of the base of the tuning fork, means including a coil and source of a-c. for cyclically impulsing the first leg of the tuning fork, a magnet secured to the second leg of the tuning fork, a magnetic escapement wheel cooperating with the magnet and having a shaft mounted in the frame, the wheel having a zig-zag magnetic path thereon so that it is progressively advanced as the magnet oscillates back and forth, the base plate being of sharply reduced section in the region between the body portion and the mounting portion so as to permit relatively free resilient movement of the body portion on which the tuning fork is mounted thereby to facilitate transfer of energy from the first leg of the tuning fork to the second leg while minimizing transfer of energy to the frame, and indicator means coupled to the escapement wheel shaft.
 4. The combination as claimed in claim 3 in which the base plate is deeply notched between the body portion and the mounting portion, the notch extending inwardly from the region adjacent the point of attachment of the tuning fork and extending parallel to the latter.
 5. The combination as claimed in claim 3 in which a relatively massive spacer block is interposed between at least one of the plates and the mounting portion of the base plate to inhibit transmission of vibrational energy from the base plate to the frame.
 6. The combination as claimed in claim 5 in which the block is in the form of porous sintered metal for damping vibrations of the mounting portion of the base plate.
 7. In a clock the combination comprising a frame, a magnetic escapement wheel having a shaft mounted in the frame, a vibrated element mounted on the frame at one of its ends, means for cyclically impulsing the vibrated member, the vibrated element having a magnet at the other end for cooperating with the escapement wheel so that the wheel is timingly advanced as the magnet oscillates back and forth, a flywheel having a hub frictionally slidable on the shaft, a manually operated starting member having means for wipingly engaging the hub to initiate rotation of the magnetic escapement wheel, and indicator means coupled to the escapement shaft.
 8. The combination as claimed in claim 7 in which the starting member is in the form of a pivoted lever having a tip which frictionally engages the hub with a wiping action, the lever including means for normally biasing the same out of engagement with the hub but manually movable into engagement therewith and with the biasing force serving to impulse the flywheeel forwardly when the wiper is manually released.
 9. The combination as claimed in claim 1 in which the shaft has a single jeweled thrust bearing at the lower end.
 10. In a clock construction the combination comprising a synethetic resin plate and a metallic plate horizontally spaced from one another, two vibrating members interposed between said plates for horizontal vibrating motion, a magnet mounted on the tip of one of said vibrating members for hOrizontal vibrating motion, a vertical escapement shaft having a magnetic escapement wheel and an inertia wheel mounted thereon in a horizontal plane, and having a worm mounted thereon for cooperation with a worm wheel, said escapement wheel having a zig-zag magnetic path for magnetic coupling with said vibrating magnet, and a regulator mounted on the metallic plate for regulating the frequency of vibration, the regulator being in the form of a small permanent magnet arranged in the vicinity of one of the vibrating members and having a screw threaded in the metallic plate for adjustably positioning the permanent magnet toward and away from the one vibrating member.
 11. The combination as claimed in claim 10 further comprising: a time gear wheel disposed in a vertical plane and coupled to the worm wheel, said gear wheel having a regulator shaft rigidly fixed to its center and extending horizontally from and perpendicular to said vertical plane a distance far enough to provide access to said shaft, thereby providing means for adjusting said time gear wheel to a reference point.
 12. The combination as claimed in claim 10 further comprising: a time gear wheel disposed in a vertical plane and coupled to the worm wheel, said time wheel having gear teeth disposed annularly with respect to the gear wheel and extending perpendicularly from said vertical plane; a vertically extending regulator shaft having a horizontally disposed gear wheel at one end for coupling to the annular gear teeth, the other end of said shaft extending a sufficient distance to provide access to it, thereby providing means for adjusting said time gear wheel to a reference point. 